Managing disturbance induced errors

ABSTRACT

In an embodiment, a memory controller may determine that one or more neighboring memory cells associated with a target memory cell in a memory device are to be refreshed. The controller may generate a command associated with refreshing the one or more neighboring memory cells. The controller may transfer the command from the memory controller to the memory device containing the target memory cell. The command may direct the memory device to refresh the neighboring memory cells and/or return one or more addresses associated with the neighboring memory cells.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/832,278 entitled “MANAGING DISTURBANCE INDUCED ERRORS,” (AttorneyDocket No. INT12-15(P51182), filed on Mar. 15, 2013, the entireteachings of which are incorporated herein by this reference.

BACKGROUND

A computing device may use one or more storage systems to storeinformation. The information may include, for example, data and/orexecutable instructions. The storage systems may include a primarystorage and a secondary storage. A primary storage may be a storage thatis directly accessible to a processor that may be contained in thecomputing device. The processor may access the primary storage via amemory bus that may contain provisions for transferring informationbetween the processor and the primary storage. A secondary storage maybe a storage that may not be directly accessible to the processor. Here,information may be transferred between the processor and the secondarystorage via one or more input/output (I/O) channels that may be part ofan I/O bus.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate one or more embodiments describedherein and, together with the description, explain these embodiments. Inthe drawings:

FIG. 1 illustrates a block diagram of an example embodiment of acomputing device;

FIG. 2 illustrates an example embodiment of a storage device that may becontained in a secondary storage;

FIG. 3 illustrates an example layout of a memory device that may becontained in a storage device;

FIG. 4 illustrates an example embodiment of a command that may be issuedto a memory device; and

FIGS. 5-8 illustrate flow diagrams of example acts that may be used torefresh one or more neighboring memory cells associated with a targetmemory cell contained in a memory device.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings.The same reference numbers in different drawings may identify the sameor similar elements. Also, the following detailed description does notlimit the invention.

A computing device may include a storage device that the computingdevice may use to store information (e.g., data, computer-executableinstructions). The storage device may store the information in avolatile and/or non-volatile storage. A non-volatile storage may be usedto store information that is to survive after power is lost to thecomputing device.

For example, a computing device may contain a processor and asolid-state disk (SSD). The SSD may provide storage (e.g., non-volatilestorage) for the computing device. The processor may use the SSD tostore information for a user of the computing device. The informationmay include, for example, data and/or applications that may be used bythe computer device. By storing the information in the SSD, theinformation may be persisted such that the information may be retainedin the SSD after power is lost to the computing device. The processormay retrieve the persisted information from the SSD after power isrestored to the computing device.

A storage device may contain one or more memory devices that may storeinformation for the storage device. A memory device may comprise one ormore arrays where an array may include one or more memory cells that maybe used to store information in the memory device.

A memory cell may be associated with an address. The address may be usedto specify a location of the memory cell in an array. Information may bewritten into and/or read from the memory cell using the addressassociated with the memory cell. For example, a memory cell in a memorydevice may be associated with a particular address (e.g., 0x100). Thememory cell may be accessed (e.g., read, written) using the address ofthe memory cell.

In some memory devices, an address may be associated with a group of oneor more memory cells. For example, a memory device may be byteaddressable where an address may be associated with eight memory cells.Here, a memory cell may store one bit of information.

In some memory devices, arrays of memory cells may be organized inmultiple dimensions (e.g., a 2-dimensional (2D) arrays, 3-dimensional(3D) arrays). Here, a group of memory cells associated with an addressmay physically reside across multiple arrays. In other words, a memoryaddress may be associated with a combination of multiple memory cellsfrom multiple arrays.

A target memory cell may be a memory cell that is a target for anoperation that may involve accessing the memory cell. An addressassociated with the target memory cell may be used to identify thetarget memory cell. For example, suppose a computing device issues aread command to a storage device to read information stored at anaddress in the storage device. The storage device may include one ormore memory devices that may contain one or more memory cells associatedwith the address that may store the information. The storage may use theaddress to identify the one or more memory cells and read theinformation from the identified memory cells. In this example, theidentified memory cells may be said to be target memory cells for theread operation.

A target memory cell may be associated with one or more neighboringmemory cells. A neighboring memory cell may include a memory cell thatmay be physically near the target memory cell. In some instances,accesses to a target cell may disturb (e.g., change) information storedat a neighboring memory cell. Such disturbances may be referred to as“disturbs”.

A system that employs one or more memory devices to store informationmay utilize one or more techniques in order to obviate one or moreeffects that may be associated with disturbs. Examples of techniquesthat may be used may include: (1) improving materials, process, and/ortechnology used to implement the memory devices in order to minimizedisturbs; (2) changing various read and/or write techniques utilized byin a memory device (e.g., changing voltages applied to a target memorycell versus other memory cells, changing a timing and/or order in whichvoltages are applied); (3) designing a controller that interfaces with amemory device to periodically refresh information (e.g., data) stored inthe memory device and/or refresh the information after certain number ofread and/or write operations performed on the memory device; and/or (4)designing error correction circuitry associated with a controller tocorrect an increased number of errors.

Note that the above techniques may be implemented entirely within amemory device or within a controller associated with a memory device.Other techniques that may be used to obviate one or more effectsassociated with disturbs may involve a memory device and a controllerassociated with the memory device.

Techniques described herein may be employed in a computing device.Examples of computing devices that may employ techniques describedherein may include, but are not limited to, smart phones, tablets,ultrabooks, laptops, mainframes, servers, and desktop computers.

FIG. 1 illustrates a block diagram of an example embodiment of acomputing device 100 that may employ various techniques describedherein. Referring to FIG. 1, computing device 100 may include variouscomponents such as, for example, processing logic 120, primary storage130, secondary storage 150, one or more input devices 160, one or moreoutput devices 170, and/or one or more communication interfaces 180.

It should be noted that FIG. 1 illustrates an example embodiment ofcomputing device 100. Other embodiments of computing device 100 mayinclude more components or fewer components than the componentsillustrated in FIG. 1. Further, the components may be arrangeddifferently than as illustrated in FIG. 1. For example, in an embodimentof computing device 100, secondary storage 150 may be contained at aremote site that provides “cloud” storage. The site may be accessible tocomputing device 100 via a communications network, such as, for example,the Internet. A communication interface 180 may be used to interface thecomputing device 100 with the communications network.

Also, it should be noted that functions performed by various componentscontained in other embodiments of computing device 100 may bedistributed among the components differently than as described herein.

Computing device 100 may include an input/output (I/O) bus 110 that mayenable communication among components in computing device 100, such as,for example, processing logic 120, secondary storage 150, one or moreinput devices 160, one or more output devices 170, and/or one or morecommunication interfaces 180. The communication may include, among otherthings, transferring, for example, control signals and/or data betweenthe components. I/O busses that may be used to implement I/O bus 110 mayinclude, for example, serial AT attachment (SATA), peripheral componentinterconnect (PCI), PCI express (PCI-e), universal serial bus (USB),small computer system interface (SCSI), serial attached SCSI (SAS), orsome other I/O bus.

Computing device 100 may include a memory bus 190 that may enableinformation, which may be stored in primary storage 130, to betransferred between processing logic 120 and primary storage 130. Theinformation may include computer-executable instructions and/or datathat may be executed, manipulated, and/or otherwise processed byprocessing logic 120.

Processing logic 120 may include logic for interpreting, executing,and/or otherwise processing information. The information may includeinformation that may be stored in, for example, primary storage 130and/or secondary storage 150. In addition, the information may includeinformation that may be acquired (e.g., read, received) by one or moreinput devices 160 and/or communication interfaces 180.

Processing logic 120 may include a variety of heterogeneous hardware.For example, the hardware may include some combination of one or moreprocessors, microprocessors, field programmable gate arrays (FPGAs),application specific instruction set processors (ASIPs), applicationspecific integrated circuits (ASICs), complex programmable logic devices(CPLDs), graphics processing units (GPUs), and/or other types ofprocessing logic that may, for example, interpret, execute, manipulate,and/or otherwise process the information. Processing logic 120 maycomprise a single core or multiple cores. An example of a processor thatmay be used to implement processing logic 120 is the Intel® Core™ i7processor available from Intel Corporation, Santa Clara, Calif.

Input devices 160 may include one or more devices that may be used toinput information into computing device 100. The devices may include,for example, a keyboard, computer mouse, microphone, camera, trackball,gyroscopic device (e.g., gyroscope), mini-mouse, touch pad, stylus,graphics tablet, touch screen, joystick (isotonic or isometric),pointing stick, accelerometer, palm mouse, foot mouse, puck, eyeballcontrolled device, finger mouse, light pen, light gun, neural device,eye tracking device, steering wheel, yoke, jog dial, space ball,directional pad, dance pad, soap mouse, haptic device, tactile device,neural device, multipoint input device, discrete pointing device, and/orsome other input device. The information may include spatial (e.g.,continuous, multi-dimensional) data that may be input into computingdevice 100 using, for example, a pointing device, such as a computermouse. The information may also include other forms of data, such as,for example, text that may be input using a keyboard.

Output devices 170 may include one or more devices that may outputinformation from computing device 100. The devices may include, forexample, a cathode ray tube (CRT), plasma display device, light-emittingdiode (LED) display device, liquid crystal display (LCD) device, vacuumflorescent display (VFD) device, surface-conduction electron-emitterdisplay (SED) device, field emission display (FED) device, hapticdevice, tactile device, printer, speaker, video projector, volumetricdisplay device, plotter, touch screen, and/or some other output device.Output devices 170 may be directed by, for example, processing logic120, to output the information from computing device 100. Outputting theinformation may include presenting (e.g., displaying, printing) theinformation on an output device 170. The information may include, forexample, text, graphical user interface (GUI) elements (e.g., windows,widgets, and/or other GUI elements), audio (e.g., music, sounds), and/orother information that may be outputted by output devices 170.

Communication interfaces 180 may include logic for interfacing computingdevice 100 with, for example, one or more communications networks andenable computing device 100 to communicate with one or more entities(e.g., nodes) coupled to the communications networks. The communicationsnetworks may include, for example, the Internet, wide-area networks(WANs), local area networks (LANs), 3G and/or 4G (e.g., 4G long-termevolution (LTE)) networks. Communication interfaces 180 may include oneor more transceiver-like mechanisms that may enable computing device 100to communicate with entities coupled to the communications networks.Examples of communication interfaces 180 may include a built-in networkadapter, network interface card (NIC), Personal Computer Memory CardInternational Association (PCMCIA) network card, card bus networkadapter, wireless network adapter, Universal Serial Bus (USB) networkadapter, modem, and/or other device suitable for interfacing computingdevice 100 to a communications network.

Primary storage 130 and secondary storage 150 may include one or memorydevices. A memory device may support, for example, serial or randomaccess to information contained in the memory device. A memory devicethat supports serial access to information stored in the memory devicemay be referred to as a serial memory device. A memory device thatsupports random access to information stored in the memory device may bereferred to as a random access memory (RAM) device.

A memory device may be, for example, a volatile or non-volatile memorydevice. A volatile memory device may be a memory device that may loseinformation stored in the device when power is removed from the device.A non-volatile memory device may be a memory device that may retaininformation stored in the device when power is removed from the device.Examples of memory devices may include dynamic RAM (DRAM) devices, flashmemory devices, static RAM (SRAM) devices, zero-capacitor RAM (ZRAM)devices, twin transistor RAM (TTRAM) devices, read-only memory (ROM)devices, ferroelectric transistor RAM (FeTRAM) devices,magneto-resistive RAM (MRAM) devices, three dimensional (3D) cross pointmemory devices (e.g., phase change memory (PCM) devices), nanowire-baseddevices, resistive RAM (RRAM) devices, serial electrically erasableprogrammable ROM (SEEPROM) devices, spin transfer torque (STT) MRAMdevices, and serial flash devices.

Primary storage 130 may be accessible to processing logic 120 via memorybus 190. Primary storage 130 may store computer-executable instructionsand/or data that may implement operating system (OS) 132 and application(APP) 134. The computer-executable instructions may be executed,interpreted, and/or otherwise processed by processing logic 120.

Primary storage 130 may be implemented using one or more memory devicesthat may store information for processing logic 120. The information mayinclude executable instructions that may be executed by processing logic120. The information may also include data that may be manipulated byprocessing logic 120. The memory devices may include volatile and/ornon-volatile memory devices.

OS 132 may be a conventional operating system that may implement variousconventional operating system functions that may include, for example,(1) scheduling one or more portions of APP 134 to run on (e.g., beexecuted by) the processing logic 120, (2) managing primary storage 130,and (3) controlling access to various components in computing device 100(e.g., input devices 160, output devices 170, communication interfaces180, secondary storage 150) and information received and/or transmittedby these components.

Examples of operating systems that may be used to implement OS 132 mayinclude the Linux operating system, Microsoft Windows operating system,the Symbian operating system, Mac OS operating system, and the Androidoperating system. A distribution of the Linux operating system that maybe used is Red Hat Linux available from Red Hat Corporation, Raleigh,N.C. Versions of the Microsoft Windows operating system that may be usedinclude Microsoft Windows Mobile, Microsoft Windows 8, Microsoft Windows7, Microsoft Windows Vista, and Microsoft Windows XP operating systemsavailable from Microsoft Inc., Redmond, Wash. The Symbian operatingsystem is available from Accenture PLC, Dublin, Ireland. The Mac OSoperating system is available from Apple, Inc., Cupertino, Calif. TheAndroid operating system is available from Google, Inc., Menlo Park,Calif.

APP 134 may be a software application that may execute under control ofOS 132 on computing device 100. APP 134 and/or OS 132 may containprovisions for processing transactions that may involve storinginformation in secondary storage 150. These provisions may beimplemented using data and/or computer-executable instructions containedin APP 134 and/or OS 132.

Secondary storage 150 may include one or more storage devices 200. Thestorage devices 200 may be accessible to processing logic 120 via I/Obus 110. The storage devices may store information. The information mayinclude computer-executable instructions and/or data. The informationmay be executed, interpreted, manipulated, and/or otherwise processed byprocessing logic 120.

The storage devices 200 may be volatile or non-volatile. Examples ofstorage devices 200 may include magnetic disk drives, optical diskdrives, random-access memory (RAM) disk drives, flash drives, SSDs,and/or hybrid drives. The information may be stored on one or morenon-transitory tangible computer-readable media contained in the storagedevices 200. Examples of non-transitory tangible computer-readable mediathat may be contained in the storage devices may include magnetic discs,optical discs, volatile memory devices, and or non-volatile memorydevices.

FIG. 2 illustrates an example embodiment of a storage device 200.Storage device 200 may be, for example, an SSD. Referring to FIG. 2,storage device 200 may include a controller 220 and storage 240.

Controller 220 may be a memory controller that may control and/or managean operation of storage 240 and/or storage device 200. Controller 220may interface with storage 240 and transfer information betweencontained in storage 240 and the controller 220. The information mayinclude commands that controller 220 may use to manage and/or control anoperation of storage 240. The information may also include data and/oraddress information. The address information may relate to locations ofmemory cells that may be contained in memory devices 300 a-n. Controller220 may employ various protocols, control signals, handshake signals,status signals, and/or other techniques to accommodate transferring theinformation between the controller 220, storage 240, and/or memorydevices 300 a-n.

Controller 220 may include device processing logic 224 and local storage226. Device processing logic 224 may include processing logic that maybe used to, for example, refresh memory cells contained in storage 240.The processing logic may include some combination of one or moreprocessors, microprocessors, FPGAs, ASIPs, ASICs, CPLDs, and/or othertypes of processing logic that may, for example, interpret, execute,manipulate, and/or otherwise process the information.

Local storage 226 may include a non-transitory tangiblecomputer-readable medium that may be used to store information that maybe processed by device processing logic 224. The medium may includevolatile and/or non-volatile storage. The information may includecomputer-executable instructions that may, for example, be executed bydevice processing logic 224 to refresh one or more memory cellscontained in storage 240 and/or perform other functions and/oroperations that may be associated with storage 240 and/or storage device200.

For example, acts associated with FIGS. 5-8 (described further below)may be encoded in one or more computer-executable instructions that maybe stored in local storage 226. Device processing logic 224 may performone or more of the acts by executing one or more of thecomputer-executable instructions.

Storage 240 may provide a volatile and/or non-volatile storage forinformation written to the storage device 200. Storage 240 may containone or more memory devices 300 a-n that may be used to store theinformation. Examples of devices that may be used to implement memorydevice 300 may include DRAM devices, flash memory devices, SRAM devices,ZRAM devices, TTRAM devices, ROM devices, FeTRAM devices, MRAM devices,3D cross point memory devices (e.g., PCM devices), nanowire-baseddevices, RRAM devices, SEEPROM devices, and serial flash devices.

A memory device 300 may store information in one or more memory cellscontained in the memory device 300. The memory cells may be organized asan array which may be multi-dimensional (e.g., 2-dimensional array,3-dimensional array). Further, groups of one or more memory cells may beassociated with addresses.

For example, a memory cell in memory device 300 may store a single bitof information. Memory device 300 may be byte addressable such that anaddress may be associated with a group of eight memory cells containedin memory device 300.

FIG. 3 illustrates an example layout of memory device 300. Referring toFIG. 3, memory device 300 may include an array 320 of memory cells 340.It should be noted that FIG. 3 illustrates an example layout of a memorydevice 300. Other embodiments of memory device 300 may include otherlayouts. For example, other embodiments of memory device 300 may containlayouts that may include multiple arrays 320.

A memory cell 340 may store information (e.g., a bit of information).Further, memory cell 340 may be associated with an address that may beused to access (e.g., read, write) information in the memory cell 340.For example, memory cell 340 a may be associated win an address “0”.Information may be read from or written to memory cell 340 a usingaddress “0”.

A memory cell in array 320 may contain neighboring memory cells. Forexample, memory cells 340 b-d may be considered neighboring memory cellsthat may be associated with memory cell 340.

Memory cell disturbs may be obviated, for example, by refreshingcontents of memory cells that may be affected (e.g., changed) due todisturbs. For example, suppose a neighboring memory cell may bedisturbed due to multiple accesses to an associated target memory cell.This situation may be obviated by periodically refreshing theneighboring memory cell.

Techniques that may be used to identify and/or refresh neighboringmemory cells associated with a target memory cell may involve a command.FIG. 4 illustrates an example command 400 that may be used to identifyand/or refresh neighboring memory cells that may be associated with atarget memory cell.

Referring to FIG. 4, command 400 may include a command identifier (ID)field 410 and target memory cell ID field 420. The command ID field 410may hold an identifier that may identify a command to be performed. Thetarget memory cell ID field 420 may hold an identifier that may beassociated with a target memory cell and may be used to identify thetarget memory cell. For example, the identifier may include an addressassociated with the target memory cell. The address may be used toidentify the target memory cell.

The command 400 may be used by a controller to identify addressesassociated with neighboring memory cells of a target memory cell. Forexample, suppose controller 220 (FIG. 2) generates a command 400 wherethe target memory cell ID field 420 includes an address of a targetmemory cell in memory device 300 a and command ID field 410 thatincludes an identifier that identifies a command that requests addressesof neighboring memory cells associated with the target memory cell.Controller 220 (FIG. 2) may issue the command 400 to memory device 300a. Memory device 300 a may acquire (e.g., read, receive) the command andprocess it. Processing may include transferring addresses of one or moreof the neighboring memory cells to the controller 220.

In another example, controller 220 may generate a command 400 thatincludes a an address of a target memory cell in the target memory cellID field 420 and an identifier associated with a command to refreshneighboring memory cells associated with the target memory cell in thecommand ID field 410. Controller 220 may issue the command to memorydevice 300 a. Memory device 300 may acquire the command 400 and processit. Processing the command 400 may include, for example, identifyingneighboring memory cells associated with the target memory cell and/orrefreshing the identified neighboring memory cells.

FIG. 5 illustrates a flow diagram of example acts that may be used torefresh one or more neighboring memory cells associated with a targetmemory cell. Referring to FIG. 5, at block 510, a determination may beperformed and based on an outcome of the determination it may bedetermined that one or more neighboring cells associated with a targetmemory cell are to be refreshed. The determination may involve varioustechniques.

For example, a technique may involve generating a random number for oneor more accesses (e.g., each access) of the target memory cell. Thedetermination may involve determining whether the generated randomnumber matches certain criteria (e.g., the random number equals apredetermined value). If the generated random number matches thecriteria, it may be determined that the neighboring memory cellsassociated with the target memory cell are to be refreshed.

In another example, a technique may involve a count associated with atarget memory cell (e.g., a count of a number of times the target memorycell is accessed). A refresh may occur when, for example, the countmatches a certain criteria.

For example, a count that measures a number of times the target memorycell is accessed may be maintained. A check may be performed todetermine whether the count has reached a predetermined value (e.g., apredetermined threshold value, an integer multiple of a predeterminednumber). After the count reaches the predetermined value it may bedetermined that the neighboring memory cells associated with the targetmemory cell are to be refreshed.

At block 512, one or more neighboring memory cells associated with thetarget memory cell are identified. The neighboring memory cells may beidentified, for example, by the memory device and/or the controller.

For example, a command containing an identifier that identifies thetarget memory cell may be sent to a memory device containing the targetmemory cell. The command may direct the memory device to refresh theneighboring memory cells. The memory device may identify the neighboringmemory cells using the identifier in the command.

In another example, a command containing an identifier that identifiesthe target memory cell may be sent to the memory device containing thetarget memory cell. Here, the command may direct the memory device toreturn one or more addresses of the neighboring memory cells. Theneighboring memory cells may be identified based on the returnedaddresses.

It should be noted that the above techniques for identifying neighboringmemory cells are examples of techniques that may be used to identifyneighboring memory cells. Other techniques for identifying theneighboring memory cells may also be used.

At block 514, the identified neighboring memory cells are refreshed.Refreshing a neighboring memory cell may include rewriting theneighboring memory cell with information that is stored in theneighboring memory cell. For example, suppose the neighboring memorycell is storing a bit set to a logical one. Refreshing the neighboringmemory cell may include writing a logical one to the neighboring memorycell.

Note that refreshing may include utilizing various features that may beassociated with a memory device containing the neighboring memory cells.For example, the memory device may support an “internal read with nodata burst” and/or a “reset only write” features. These features may beused when refreshing the neighboring memory cells.

For example, suppose that the target memory cell and neighboring memorycells are contained in memory device 300 a. Controller 220 may determinethat one or more of the neighboring memory cells are to be refreshed.The determination may be performed using one or more of theabove-described techniques. The controller 220 may generate a command400 associated with refreshing the neighboring memory cells.

The command 400 may include, for example, a command that may directmemory device 300 a to (1) refresh the neighboring memory cells and/or(2) return one or more addresses associated with neighboring memorycells. After generating the command 400, controller 220 may transfer thecommand to memory device 300 a. Memory device 300 a may receive thecommand 400 and process it. Processing the command 400 may include, forexample, refreshing the neighboring memory cells and/or returning one ormore addresses associated with the neighboring memory cells. If thememory device 300 a returns one or more addresses associated with theneighboring memory cells, the controller 220 may receive the addressesand refresh the neighboring memory cells, such as described above, usingthe received addresses.

FIG. 6 illustrates another flow diagram of example acts that may be usedto refresh one or more neighboring memory cells associated with a targetmemory cell. Referring to FIG. 6, at block 610, a controller maydetermine that neighboring memory cells associated with a target memorycell are to be refreshed. The controller may make the determinationusing various techniques, such as described above.

For example, suppose the target memory cell is contained in memorydevice 300 a. Controller 220 may use one or more techniques to determinewhether neighboring memory cells associated with the target memory cellshould be refreshed. The techniques may include one or more of thetechniques described above. Based on an outcome of the techniques, thecontroller 220 may determine that the neighboring memory cells should berefreshed.

At block 612, the controller may issue a neighbor refresh command to amemory device that contains the target memory cell. The neighbor refreshcommand may be used to direct the memory device to refresh neighboringmemory cells associated with the target memory cell.

For example, continuing the above example, controller 220 may generate acommand 400 (FIG. 4) that contains an identifier that identifies aneighbor refresh command in command ID field 410 and an addressassociated with the target memory cell (in memory device 300 a) in thetarget memory cell ID field 420. After generating the command 400,controller 220 may issue the generated command 400. Issuing the commandmay include transferring (e.g., sending) the command 400 to memorydevice 300 a. The controller 220 may transfer the command to the memorydevice 300 a via, for example, a bus that may interconnect thecontroller 220 with the memory device 300 a.

At block 614, the memory device may acquire the memory refresh command.For example, continuing the above example, memory device 300 a mayacquire the command 400 by reading the command from the bus.

At block 616, the memory device containing the target memory cellrefreshes one or more neighboring memory cells associated with thetarget memory cell. Refreshing may include identifying the neighboringmemory cells and rewriting information contained in the neighboringcells, such as described above.

For example, continuing the above example, suppose memory device 300 aacquired the command 400 and processes it. Processing may include deviceprocessing logic 224 examining the target memory cell ID field 420 toidentify the target memory cell. After identifying the target memorycell, device processing logic 224 may identify one or more neighboringmemory cells associated with the identified target memory cell. Memorydevice 300 a may then refresh information stored in the identifiedneighboring memory cells, such as described above.

FIG. 7 illustrates another flow diagram of example acts that may be usedto refresh one or more neighboring memory cells associated with a targetmemory cell. Referring to FIG. 7, at block 710, a controller maydetermine that neighboring memory cells associated with a target memorycell are to be refreshed. The controller may make the determinationusing various techniques, such as described above.

At block 712, the controller may issue a command to a memory devicecontaining the target memory cell to get one or more addresses ofneighboring memory cells associated with the memory device. For example,suppose memory device 300 a contains the target memory cell. Controller220 may generate a command 400 that contains an identifier thatidentifies a neighbor refresh command in command ID field 410 and anaddress associated with the target memory cell in the target memory cellID field 420. Controller 220 may transfer the generated command 400 tomemory device 300 a.

At block 714, the memory device acquires the command and transfers oneor more addresses associated with the neighboring memory cells to thecontroller. For example, continuing the above example, controller 220may transfer the generated command 400 to memory device 300 a via a bus.Memory device 300 a may read the command 400 from the bus.

After reading the command 400, memory device 300 a may process it.Processing the command may include identifying one or more addressesassociated with the neighboring memory cells. The neighboring memorycells may be identified based on a technique that the memory device 300a may employ to identify neighboring memory cells. The technique mayinvolve, for example, calculating the addresses of the neighboringmemory cells using an algorithm.

After identifying the addresses of the neighboring memory cells, memorydevice 300 a may transfer the identified addresses to the controller220. Transferring may include, for example, messaging, handshaking,various protocols, and/or other techniques that may be used to transferthe identified addresses between the memory device 300 a and thecontroller 220.

At block 718, the controller acquires addresses of neighboring memorycells and refreshes the neighboring memory cells associated with thetarget memory cell using the acquired addresses. For example, continuingthe above example, suppose that memory device 300 a transfers theaddresses, identified at block 714, to controller 220 via a bus.Controller 220 may acquire the identified addresses by reading theaddresses from the bus. After acquiring an address, controller 220 mayrefresh a memory cell associated with the address by, for example,rewriting information stored in the memory cell, such as describedabove.

FIG. 8 illustrates another flow diagram of example acts that may be usedto refresh one or more neighboring memory cells associated with a targetmemory cell. Referring to FIG. 8, at block 810, a controller maydetermine that neighboring memory cells associated with a target memorycell are to be refreshed. The controller may make the determinationusing various techniques, such as described above.

At block 812, the controller may identify neighboring memory cells basedon a technique that may be used by a memory device containing the targetmemory cell to identify the neighboring memory cells. For example,suppose controller 220 has determined that neighboring memory cellsassociated with a target memory cell in memory device 300 a are to berefreshed. Controller 220 may identify the addresses of the neighboringmemory cells using a technique that may be employed by memory device 300a to identify the neighboring memory cells.

At block 814, the controller refreshes the identified memory cells. Forexample, continuing the above example, controller 220 rewriteinformation contained in the identified addresses of the neighboringmemory cells, such as described above.

The foregoing description of embodiments is intended to provideillustration and description, but is not intended to be exhaustive or tolimit the invention to the precise form disclosed. Modifications andvariations are possible in light of the above teachings or may beacquired from practice of the invention. For example, while a series ofacts has been described above with respect to FIGS. 5 through 8, theorder of the acts may be modified in other implementations. Further,non-dependent acts may be performed in parallel.

Also, the term “user”, as used herein, is intended to be broadlyinterpreted to include, for example, a computing device (e.g., fixedcomputing device, mobile computing device) or a user of a computingdevice, unless otherwise stated.

It will be apparent that one or more embodiments, described herein, maybe implemented in many different forms of software and/or hardware.Software code and/or specialized hardware used to implement embodimentsdescribed herein is not limiting of the invention. Thus, the operationand behavior of embodiments were described without reference to thespecific software code and/or specialized hardware—it being understoodthat one would be able to design software and/or hardware to implementthe embodiments based on the description herein.

Further, certain features of the invention may be implemented usingcomputer-executable instructions that may be executed by processinglogic, such as, for example, device processing logic 224. Thecomputer-executable instructions may be stored on one or morenon-transitory tangible computer-readable storage media, such as, forexample local storage 226. The media may be volatile or non-volatile andmay include, for example, DRAM, SRAM, flash memories, removable disks,non-removable disks, and so on.

No element, act, or instruction used herein should be construed ascritical or essential to the invention unless explicitly described assuch. Also, as used herein, the article “a” is intended to include oneor more items. Where only one item is intended, the term “one” orsimilar language is used. Further, the phrase “based on” is intended tomean “based, at least in part, on” unless explicitly stated otherwise.

It is intended that the invention not be limited to the particularembodiments disclosed above, but that the invention will include any andall particular embodiments and equivalents falling within the scope ofthe following appended claims.

1. A method comprising: determining at a memory controller that one ormore neighboring memory cells associated with a target memory cell areto be refreshed; generating a command associated with refreshing the oneor more neighboring memory cells, the command including an identifierthat identifies the target memory cell; and transmitting the commandfrom the memory controller to a memory device that contains the targetmemory cell.
 2. The method of claim 1, wherein the command is to directthe memory device to refresh the neighboring memory cells.
 3. The methodof claim 1, wherein the command is to direct the memory device to returnone or more addresses associated with the neighboring memory cells. 4.The method of claim 3, further comprising: acquiring the one or moreaddresses associated with the neighboring memory cells from the memorydevice.
 5. The method of claim 4, further comprising: refreshing one ormore neighboring memory cells associated with the acquired one or moreaddresses.
 6. The method of claim 1, wherein determining furthercomprises: generating a random number for an access of the target memorycell; and determining whether the generated random number matches apredefined criteria.
 7. The method of claim 1, wherein determiningfurther comprises: maintaining a count associated with accessing thetarget memory cell; and determining whether the maintained count matchesa predefined count. 8-10. (canceled)
 11. One or more tangiblenon-transitory computer-readable mediums storing executable instructionsfor execution by one or more processors, the medium storing: one or moreinstructions for determining at a memory controller that one or moreneighboring memory cells associated with a target memory cell are to berefreshed; one or more instructions for generating a command associatedwith refreshing the one or more neighboring memory cells, the commandincluding an identifier that identifies the target memory cell; and oneor more instructions for causing transmission of the command from thememory controller to a memory device that contains the target memorycell.
 12. The medium of claim 11, wherein the command directs the memorydevice to refresh the neighboring memory cells.
 13. The medium of claim11, wherein the command directs the memory device to return one or moreaddresses associated with the neighboring memory cells.
 14. The mediumof claim 13, further storing: one or more instructions for acquiring theone or more addresses associated with the neighboring memory cells fromthe memory device.
 15. The medium of 14, further storing: one or moreinstructions for refreshing one or more neighboring memory cellsassociated with the acquired one or more addresses.
 16. The medium ofclaim 11, further storing: one or more instructions for generating arandom number for an access of the target memory cell; and one or moreinstructions for determining whether the generated random number matchesa predefined criteria.
 17. The medium of claim 11, further storing: oneor more instructions for maintaining a count associated with accessingthe target memory cell; and one or more instructions for determiningwhether the maintained count matches predefined count.
 18. (canceled)19. A system comprising: a controller to: determine that one or moreneighboring memory cells associated with a target memory cell are to berefreshed, generate a command associated with refreshing the one or moreneighboring memory cells, and transmit the command to a memory devicethat contains the neighboring memory cells and the target memory cell.20. The system of claim 19, wherein the command is to direct the memorydevice to refresh the neighboring memory cells.
 21. The system of claim19, wherein the command is to direct the memory device to return one ormore addresses associated with the neighboring memory cells.
 22. Thesystem of claim 21, wherein the controller is to further: acquire theone or more addresses associated with the neighboring memory cells fromthe memory device, and refresh one or more neighboring memory cellsassociated with the acquired one or more addresses.
 23. A memory systemcomprising: a memory device; and a controller to: determine that one ormore neighboring memory cells associated with a target memory cell inthe memory device are to be refreshed, the determining being performedbased on a technique used by the memory device to identify theneighboring memory cells, generate a command associated with refreshingat least one of the neighboring memory cells, and transmit the commandto the memory device, the command causing the memory device to refreshthe at least one of the neighboring memory cells.
 24. The memory systemof claim 23, wherein the controller further comprises: device processinglogic; and a local storage, and wherein the local storage stores one ormore computer executable instructions that when executed by the deviceprocessing logic causes the memory system to perform at least one of thedetermine, generate, or transmit.
 25. A memory device comprising: logicto: acquire a command to refresh one or more neighboring memory cellsassociated with a target memory cell, the one or more neighboring memorycells and the target memory cell being contained in the memory device,and identify the one or more neighboring memory cells based on thetarget memory cell, and refresh the identified one or more neighboringmemory cells.
 26. The memory device of claim 25, wherein the commandincludes an identifier that identifies the target memory cell, andwherein one or more neighboring memory cells are identified based on theidentifier.
 27. The memory device of claim 26, wherein the identifierincludes an address of the target memory cell.